Since automobiles are a primary mode of transportation for many people today, paving the roads to keep them in a good condition has become increasingly important. Among the suitable paving materials, asphalt and asphalt mixtures such as asphalt-rubber mixtures and asphalt-polymer mixtures are popular for their physical properties. The rubber-asphalt mixture, which contains recycled crumb rubber mixed into asphalt, is especially popular because it provides a use for scrap tires, which can pile up and become an environmental problem.
To form the rubber-asphalt, scrap tires are mixed with paving grade liquid asphalt at a temperature of approximately 400° F. The resulting liquid is then sprayed onto a surface at 385–400° F. or used as a binder in hot mix asphalt. When the hot rubber-asphalt molecules come in contact with the air and the road surface, both of which are much cooler than the rubber-asphalt, a thick cloud of emissions is released into the air. The amount of emissions is especially large for rubber-asphalt compared to other types of asphalt paving materials. Although emissions from the spraying of rubber-asphalt mixtures have not been proven to have significant health effects, they adversely affect the atmospheric air quality.
This adverse effect of rubber-asphalt paving can be reduced by installing a vacuum hood in a paving truck. The vacuum hood inlet is located near where the rubber-asphalt is sprayed, and is thereby able to suck up a lot of the emissions. The emissions are then filtered before being released back into the atmosphere.
Although the vacuum pump system helps reduce the amount of emissions released into the atmosphere, installation of a full vacuum pump system on a paving truck can be costly. Furthermore, the filter system has to be changed periodically for the vacuum pump system to work. If the filter system is not changed in time, it could result in the release of the emissions back into the atmosphere. Thus, an alternative method/system that does not have these disadvantages is desired.